1. Field of the Invention
The present invention relates to a high throughput biomolecular screening system and method that use a label independent optical detection technique to interrogate biosensors which are incorporated within the wells of a microplate. In the preferred embodiment, the high throughput biomolecular screening system includes automated instruments for dispensing, mixing, incubating, microplate handling, and implementing measurement protocols to provide high throughput detection and analysis of biomolecular interactions that take place on the biosensors in the microplate.
2. Description of Related Art
Today many areas of biological research utilize label free detection technologies to help perform sensitive and time-constrained assays. A typical assay involves the detection of a chemical/biochemical compound (drug candidate) binding to an immobilized molecule (the therapeutic target) at the surface of individual optical sensors (biosensors) located at the bottom of each well in a disposable microplate. And, the potential for using label free detection technologies to perform high throughput screening (HTS) assays in the drug discovery process was recently discussed in the following article:                John Comley “LABEL-FREE DETECTION-New Biosensors Facilitate Broader Range of Drug Discovery Applications'”, Drug Discovery World, Winter 2004/5, pages 63-74.        
In this article, one of the systems described utilizes a label free detection technology based on Surface Plasmon Resonance (SPR). For instance, U.S. Pat. No. 5,313,264 assigned to Pharmacia Biosensor AB discloses an analytical system that uses SPR and microfluidics to detect biomolecular interactions in real time on four sensing areas. In addition, U.S. Patent Application No. 2003/0003018A1 assigned to Prolinx Incorporated discloses instruments and systems that use miniaturized SPR sensors to enable the real time analysis of molecular interactions. Because, both of these systems are designed for real time kinetic analysis of molecular interactions, they have limited multiplexing capabilities which limits their throughput such that they cannot be used in HTS. Furthermore, these systems do not use standardized SBS 96, 384 or 1536 microplates. The first drawback is also true for screening systems based on non-optical detection principles (Cf. John Comley's article). Accordingly, there is a need to provide a label-free technology that enables the label free detection of a bio-chemical interaction between a drug compound and a biomolecule in high throughput primary screens. This need and other needs are satisfied by the high throughput biomolecular screening system and method of the present invention.